Urea fertilizer is commonly used as a source of nitrogen in agriculture. Urea is degraded by the enzyme urease, an enzyme that is ubiquitous in agricultural systems. Urease degradation of urea results in the loss of nitrogen from soil as ammonia in a process called volatilization. Different approaches have been implemented to prevent nitrogen loss from volatilization, including the use of the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT). Liquid formulations containing NBPT for use in reducing nitrogen volatilization comprise are known, and for example are sold under the trademarks AGROTAIN™ and ARBORITE™. Efficient and cost-effective compositions and methods for reducing nitrogen volatilization of urea fertilizers are desirable.